伊尔尔吧， 一战结束，遛遛狗

sdcar2010

13. DS有图，就是一个圆套了一个正方形，边长为x（题目写的就是x,)，问是否能够求阴影部分面积。阴影是圆与正方形之间的边围成的四个山丘形中的一个。就是四分之一的圆弧与正方形的一条边围成的那部分。
（1）已知正方形面积是8π
（2）阴影部分的面积是：一个式子（不记得了，是关于x的函数，类似12-3x之类的这种。）

1) sufficient
2) insufficient

Choose A.

The shaded area = 1/4 * [area of the circle - area of the square] = 1/4 *[pai * x^2/2 - x^2]

1) 8n = x^2.  So the shaded area = 1/4 * [pai/2 -1] * 8n = (pai - 2)*n

sdcar2010

14. PS，已知P,Q都是整数，用q去除p余数为q/2。求q
（1）q是质数
（2）q<17

p = m*q + q/2.  So q is an even number.

1) q is prime.  Then q = 2.  sufficient
2) q<17, then q could be 2, 4, ... 16.  Insufficient.

Choose A.

sdcar2010

Kevin: Good job!

AlohaDJ

PS，k=m(m+4)(m+5)一定能被以下哪个数整除：3，5，6. 选项就是只有第一个，只有第二个，第一个和第二个这种类型的。我选只能被3整除

The answer is 6 since (m+4) and (m+5) are consecutive numbers.  So one of them is even and contains a factor of 2. In addition, m, m+4, and m+5 contains a factor of 3.  So their product contains factors of 2 and 3.

这道题的answer应该是，包括3和6两个数字的选项，right?
Thanks!!

sdcar2010

PS，k=m(m+4)(m+5)一定能被以下哪个数整除：3，5，6. 选项就是只有第一个，只有第二个，第一个和第二个这种类型的。我选只能被3整除

The answer is 6 since (m+4) and (m+5) are consecutive numbers.  So one of them is even and contains a factor of 2. In addition, m, m+4, and m+5 contains a factor of 3.  So their product contains factors of 2 and 3.

这道题的answer应该是，包括3和6两个数字的选项，right?
Thanks!!

-- by 会员 AlohaDJ (2010/12/29 1:08:47)

You are right.

AlohaDJ

Thanks!!
LZ's memory is so cool!
sdcar NN is so N!

supersolarbear

lz牛逼，M49还能710.

梦离ouzi

LZ实在V5

梦离ouzi

Sdcar.是不是教授阿.英文这么厉害,数学也是大N.崇拜

nalanxingde951

条件1可以推出d=2^8.答案应为D.